Carbureter for explosive-engines.



PATENTED SEPT. 25, 1906.

'J.. B. DUNLOP & J. B. DUNLOP, JR. GARBURETER FOR EXPLOSIVE ENGINES. APPLICATION FILED JUNE 22,1903.

UNITED STATESTPATAENT OFFICE.

JOHN BOYD DUNLOP AND JOHN BOYD DUNLOP, JR. OF DUBLIN, IRELAND CARBUBETER FOR EXPLOSlVE-ENGINES.

Specification of Letters Patent.

Patented Sept. 25 1906.

Application filed June 22.1903. Serial No. 162,623.

To all whom it may concern:

Be it known that we, JOHN BOYD DUNLOP and JOHN BOYD DUNLOP, Jr. subjects of the King of England, residing at Dublin, Ireland, have invented certain new and useful Improvements in Carbureters for Explosive- Engines, of which the following isaspecification.

This invention relates to carbureters for internal combustion engines, and refers chiefly, though not exclusively, to carbureters intended for use on motorvehicles.

The invention has for its chief object to so construct the carburetor that it will maintain a correct and uniform mixture which will not be affected by either altering the opening of the throttle or changing the speed of the engine.

With carbureters in general use the strength or composition of the mixture varies with the speed of the engine, the quantity of petrol or other fuel sucked into the engine at 'each stroke being small in proportion to the air when the engine is running slowly and the throttle partially closed, whereas when the engine is running fast and the throttle fully open the quantity of petrol is large in proportion to the air. According to the present invention these objectionable features are obviated, and when the mixture has once been adjusted the proportions thereof remain constant for all speeds of the engine and at all degrees of throttle-opening. In order to accomplish this, there is disposed in the fuel duct or spray-tube, which communicates with the float or constant-level chamber and with the mixing-chamber, one or more baffles which impede the flow of petrol more or less, according as the speed of the engine is high or low. Consequently as the suction of the piston is increased or decreased the 0bstruct-' ive action of the baffles increases or decreases'in a corresponding degree, and thus the relative proportions of air and petrol are kept uniform under all conditions.

In place of or in addition to regulating the flow of petrol, as above described, the supply of air may be adjusted andregulated by means of an adjustable gate-valve or its equivalent, preferably in the form of a flat spring or other plate, which can be acted upon by the suction to open to a greater or less extent as the suction increases or decreases.

With reference to the accompanying draw- .ing, in which is shown a preferred construc .ning fast.

tion of the apparatus suitable for use in a motor-vehicle, A is the floatchamber, in which is disposed a cork or other fl'oat A.

B is the baffle situated in the fuel-duct or spray-tube C. i

D is the mixing-chamber, E the air-supply tube, and F a gate-valve or spring-plate adjustably secured therein, and G is the conduit or mixture-pipeleading to the engine cylinder or cylinders.

The fuel-duct C is inclined, as shown in the drawing, and is provided with two gaps or openings C and of which the gap G communicates with the lower part of the floatchamber A and the other enters the mixing or vaporizing chamber D at an angle to insure the rapid mixing of the air and petrol. In the upper end of the fuel-duct C is disposed an adjustable screw H, which engages with a corresponding internal screw-thread in the tube and is provided with a knob or handle H, by which a jet or spray nozzle C in the tube C can be adjusted, so as to regulatethe amount of petrol passing into the mixing-chamber at each operation. The tube 0 is extended down below the base of the float-chamber and is provided with a screw-cap C, by removing which the petrol in the float-chamber can be run off, if desired.

The baffle for impeding the passage of the petrol from the float-chamber to the vaporizing-chamber is conveniently disposed in the feed-tube between the two gaps C and C" and may consist of cups or plates, ridges or grooves, the cups or plates being perforated, if desired, or spaces may be left between the edges of each plate or cup and the sides of the passage in the tube. In all cases it is preferred that the free edges of the baffies should be inclined and project against the stream of fuel, so as to break it up into small eddies or currents and prevent. more effectually the excessive flow of petrol when the engine is run- In its preferred form, as shown in the drawing, the bafiie consists of a piece of Wire or thin rod B, having undercut or saw teeth B, and the baffle is placed in the tube in such a manner that it can readily be re- 105 moved when desired for cleansing and other purposes As stated above, the function of the baffle B is to produce a series of eddies or returncurrents in the stream of petrol passing through the feed-tube C, and the resistance to the flow of petrol is due to the collisions between such eddies or return-currents and the main stream. It is clear that the strength or power of sucheddies depends upon the. 'force with which the stream of pea.

trol impinges on the steppedface of the baffle B and that the said eddies will have a much greaterresisting eiiect when the flow of petrol is rapid than when such flow is slow. When the motor is "running at low speed, the flow .of petrol through the feed-tube is so slow that :the very slight eddies or return-currents set petro and which tend to resist orhindersuch of in flow in direct proportionto the rate creaseof the initial flow thereof, a

We prefer to adjust and regulate the flow of petrol by the meansabove described; but in'place of or in addition to regulating "the flow of petrol we may adjust and regulate the quantity of air drawn in'at each operation. For this purpose a s ring-plate F is'disposed in the air-supply tube E, to which it is connected by studs, rivets, or in any other convenient manner. The plate F is adjusted in position by a set-screw E, so that by causing the plate to extend a greater or less extent across the pipe the requisite quantity of air required to give a correct mixture may be obtained. The plate is acted upon by the inrus'h of air and opens to a greater or less extent as the suction of the piston in the engine-cylinder increases or diminishes, and thus the air and petrolare kept in correct proportions irrespective of the varying speed of the engine and the varying de me ofopening of the throttle-valve. It wibe noticed that the regulation above described is effected entirely automatically and without any mechanical connection to the baffie within the spray-pipe or fuelductthat is, the present invention. does not require any such mechanical means as a lever or rod for- -varying the position of'the device'by which 1 the supply of fuel to the mixing-chamber is regulated. The Pplate F may be placed anywhere between t nozzle: I

Petrol or other fuel isadmitted to the floatchamber A b a pipe or tube A and the supis' contro led by a cork or other float A, which'isguided in the chamber b means of a spindle: A and the upper end of the spindle is .adaptedto fit in a valve-seating A on the e air-inlet and jet or spray rni et-p'pe, so that the quantity of fuel in the chamber remains constant,

The mixture is led from the mixing or vnpoiinng chamber D by the pipe G, which However, asthe suction of the est te? communicates by suitable pipes ,or conduits with the cylinder or cylinders of the en e.

What we claim as our invention, an de- I sire to secure by Letters Patent, is'

1. In a spray-carbureter, the combination with a float-chamber and a mixing-chamber,- of a fuel-pipe between the chambers and having a nozzle at the endo' ening into the mixing-chamber, and a baffle 1n the fuel-pipefor automatically regulating without adjustment the flow of fuel into the mixing-chamthe quantity of air drawn into that chamberin cpnstant proportions independently ofthe speed of the engine: and for all degrees of opening, of the throttle.

'3. In a spray-,carbureter, the combination with a mixing-chamber having a suitable airinlet, and a duct for supplying hydrocarbon to said chamber, of means for regulating the admission of air to said chamber, and means Within said duct for regulating the supply of hydrocarbon to said chamber, said air and hydrocarbon regulating means being independently actuated by suction through the mixing-chamber.

. 4. In aspray-carbureter, the combination with a hydrocarbon chamber and armixingchamber, of means arranged between said. chambers for-retarding the flow of hydrocarbon intothe mixing-chamber and adapted to the rapidity of "movement of the hydrocarbon.

' 5. In a spray carbureter, the combination- With a hydrocarbon-chamber and a mixingchamber, of means arranged between said fuelinto the mixing-chamber relatively to .and automatically maintaining the mixture act with a force varying with variations in chambers for retarding theflowof hydrocarbon into the mixing-chamber and adapted to act with increasingforceas the movement of the hydr ocarbon is accelerated. I

- 6. In a spray-carbureter,the combination with a hydrocarbon-chamber and a mixingchamber, of means arranged wholly within a duct intermediate of said chambers for re tarding the flow of'hydrocarbon into the mixing-chamber and adapted to act, with a force proportionate to the rapidity of movement of the hydrocarbon through such duct.

7 In a spray-carbureter, thecombination with a float or fuel-supply chamber and a vaporizing or mixture chamber, of a fuel-conduit between the chambers, a nozzle at the inlet to the mixing-chamber, and a baiiie arran ed entirely within the conduit between sai nozzle and the fuel-chamber and acting with a force depending on the rapidity of movement of the fuel-through said conduit, substantially as and for the purpose described.

8. In a spray-carbureter the combination with a float-chamber and a vaporizing-chamber, of an inclined fuel-pipe communicating With both chambers, a rod disposed in the pipe and having notches or serrations directed against the stream of fuel for the purpose of regulating the flow of fuel into the mixingchamber thereby causing the strength of the mixture to remain constant for all speeds of the engine and at all degrees of opening of the throttle.

9. In a spray-carbureter the combination with a float-chamber and a vaporizing-chamber, of an inclined fuel-pipe havin a gap communicating with the fioatham er and another gap communicating with the mix ing-chamber, a fuel-nozzle in the pipe adjacent to the second gap, means for controlling the nozzle, a.bafl"le in the pipe having free edges inclined against the stream of fuel, an air-pipe and means in the air-pipe for regulatin the quantity of air drawn into the mixing-c amber at each operation substantially as and for the purpose described.

10. In a spray-carbureter the combination with a float-chamber and a vaporizing-chamber, of an inclined fuel-pipe having a gap communicating with the float-chamber and another gap communicating with the mixing-chamber, a fuel-nozzle in the pipe adja- 7 cent to the second gap, means for controlling the nozzle, a baflle in the pipe having free edges inclined against the stream of fuel, an

air-pipe, an adjustable plate in the air-pipe, for regulating the quantity of air drawn into the mixingchamber at each operation and means for adjusting the plate substantially as described.

11. In a spray-carbureter the combination with a float-chamber and a vaporizing-chamber, of, an inclined fuel-pipe having a gap communicating with the float-chamber and another ap communicating with the mixing-cham er, a fuel-nozzle in the pipeadjacent to the second gap, means for controlling the nozzle, a baflie in the pipe having free edges inclined against the stream of fuel, an air-pipe, a screw for a ustmg the position of the plate substantially as and for the purpose described.

ipring-plate in the air-pipe and a 12.- In-a spray-carbureter thecombination with a float-chamber and a vaporizing-chamber of an inclined, fuel-pipe communicatin by separate gaps withthe float-chamber an the va orizing-chamber, a nozzle in the ipe, a regu ating-screw for the nozzle, a be e in the tube having teeth inclined against the stream of petrol, a screw-cap closing the lower end of the fuel-pipe, an -air-pipe, a springlate disposed. in the air-pipe and a screw or adjusting the position of the plate substantially as and for the purpose described.

In testimony whereof we have signed our names to this specification in the presence of two subscribin witnesses.

JOHN OYD DUNLOP. JOHN BOYD DUNLOP, JUNIOR.

Witnesses:

RUFUS WATERMAN, ARTHUR DONN PIATT. 

